Device for overcoming the dead-point position of cycle-cranks.



PATBNTBD MAY 19, 1903;

E. JOHOW. v DEVICE POR OVERCOMING THE DEAD POINT POSITION OP CYCLE CRANKS.

APPLICATION FILED JAN. 27, 1903.l

PATENTED IIIIIIl I9, 1903.

E. JOEOW. DEVIOE EOE OVEEOOMING. TEE DEAD POINT POSITION OE OYOLE OEIIIIKS.l

APPLIATION FILED JAN. 27, 1903.

2 SHEETS-SHEET 2.

PATENT Patented May 19, 1903.

OFFICE.

- EMIL .lOl-IOW, OF BERLIN, GERMANY.

DEVICE FOR OVERCOMING THE DEAD-POINT POSITION 0F CYCLE-CRANKS.

SEECIFICATION forming part of Letters Patent N0. 728,240, dated May 19, 1903. Application led January 27,190.3. Serial No. 140.757. (No model.)

1ro all whom it may cotcern: l l I Be it known that I, EMIL JOHOW, architect, a subject of the German Emperor, and a resi,-

dent at No. 31 Elbingerstrasse, in the city of Berlin, Kingdom ofPrussi-a, German Empire, have invented certain new and useful Improvements in Devices for Overcoming the Dead-Point Positions of Cycle-Granite,l of which the following is a specification.

The present invention relates to devices for overcoming dead-centers of pedal-cranks or bicycles when the latter are positioned in ay substantially verticaldiameter. Itis known that the bicycle rider acts upon the pedalcranks to the greatest advantage when said pedal-cranks are in asubstantially horizontal diameter, but that the pedal-cranks are car-- ried through the'vertical diameter only by the momentum of the rotation of the cranks without any exertion or help of the rider.

One of the objects of the present invention, therefore, is to overcome thisdefect; and the nature of the invention consists of devices' substantially as described hereinbelow and illustrated by the accompanying drawings, of

, under the tension of a helical spring 20 at illustrating-the device applied top a bicycle;y Fig. 2, a vertical Which- Figure 1 is a side view cross-section in the axis of the pedal-shaft of the device; Fig. 3, a top view'of a frame limiting the stroke of the spring-acted levers. Fig. 4 illustrates'the arrangements for bringing the device into and out of operation. Fig.- 5 is a detailed view of the. end of the pedalcrank, showing the device for receiving the stroke ofthe spring-acted levers. Figs. 6 and 7 illustrate the arrangement for supporting and releasing the axis of the device. Figs. 8 and 9 illustrate the connection of the saddlebeam with the operating-rod. Fig. lO illustrates the arrangement for adjusting the tension of the spiral springs of the device.

Similar ligures of referenceindicate corresponding parts throughout the several views.

1 in Figs. 1 and 2 is the upright of the bicycle-frame, and 2 in Fig. 1 is the horizontal rod of the bicycle-frame.

3 illustrates the pedal-shaft, provided With the pedals 4 and the sprocket-wheel 5. A pair of pinions or gears 6 are keyed to the pedal-shaft. The pedal-shaft runs in a hub 7, provided with ordinary ball-bearings. Rest- Secured to a sleeve rotatable on the shaft 3 is a pair of spiral springs 13, the outer ends of which extend in the form of rods 14 and are provided with contact-strips l5, located in the path of rotation of the contact-rollers 12, so that during the rotation of the shaft 10 and gear-wheels 11 the contact-rollers 12 will come in 'contact -With the forward surface of Vthe contact-strips l-andpforce the lever 14 backward until the contact-'rollers 153V leave the said contact-strips 15, Whereafter the lever 14 will be forced forward ou account of vthe tension of the spiral springs 13. The upper end of the levers 14 is provided with a head, into which is set a pair of, bent levers 17 and adj ustably secured therein by means of a set-screw 16. The ends of these bent levers 17 are provided with a hammer 18, which at times is forced against an anvil, held the end of the pedals 4. The movement of vthe levers 14 is guided and limited by two pairs of guide-rods 21, rigidly secured to the frame'of the bicycle by means of collars 22 and22.`

p The casing 7, containing the pedal-shaft 3,

is provided on each side withan oblong slotted extension 23,'forming the guideway for the axle l0of the auxiliary device.l Secured to this extension is a 'lever' 26, pivoted on a pin 27, which lever 26 is` under pressure of a spiral spring 2,8. vThe pinions-6 on the pedal-shaft 3 are provided with an auxiliary tooth 29.

Secured tothe sleeves carrying the spiral springs 13 is a frame 30, fromwhich a wire rope or cord is carried over a roller 32..to a take-up roller 33 on the horizontal bar 2. The

collar supportingthis roller 33 is extended upwardly, forming a disk 34 and provided With teeth, into which enters a dog 36 of a lever 35.

The saddle is secured to the saddle-beam, which glides in the upright part 1 of the bicycle-frame and contains a rod 37 in a tube 38, secured to the saddle-beam by means of a collar 39.` The lower head 40 of the rod 37 is provided with guide-rollers 40 and 42 and with a pin 43, which enters into a yoke provided on the casing 9, containing and supporting axis l0 of the auxiliary device.

The operation of the device is as follows: As soon as a rider mounts the saddle of a bicycle the rod 37 is depressed, the point 43 carries casing 9 against the pressure of the helical springs 8 downward and brings the gears ll in mesh with the pinions 6 of the pedal-shaft. Duringtherotationofthepedalshaft, and therefore the rotation of the gears l1, the contact-rollers l2 will act against the contact-strips 15 of the levers 14 and force this lever backward to the extent of the length of said contact-strips l5, and as soon as one of the contact-rollers leaves the said contactstrip l5 the levers 14 will bound forward and the head 18 will meet the anvil 19 at the end of the pedal-crank, which is now at or near its vertical diameter, and will support and help to carry the pedal-crank through this vertical diameter. As the shaft l0 of the auxiliary device is normally supported by the lever 26, an auxiliary tooth 29 is provided on the pinion 6, which will release the lever 26 at each revolution of the pedal-shaft, but the gears ll will not come into mesh with the pinion 6 unless the rider has mounted the wheel, and thereby forces downward the rod 37.

In order to increase or decrease the tension of the spiral springs 30, the lever 35 on the horizontal bar 2 of the bicycle-frame may be turned back or forth and retain its position by means of the dog 36 entering the teeth of the disk 34.

What is claimed as new and useful, and desired to be secured by Letters Patent, is-

l. In a device for overcoming dead-centers, the combination with a pedal-shaft, of pinions keyed thereto, spiral springs rotatably carried thereon, operating-levers secured to the outer ends of said spiral springs, contactstrips on said operating-levers, an auxiliary device adapted to be engaged by said pinions and to act upon said contact-strips, a hammer on the end of each operating-lever, pedalcranks on the pedal-shaft and an anvil on the end of each of said pedal-cranks and adapted to receive the stroke of said hammer when said pedal-cranks pass through the substantially vertical diameter.

2. In a device for overcoming dead-centers, the combination with a pair of rotatable sleeves on a pedal-shaft, of spiral springs secured to said sleeves, a frame 30 connected to said sleeves, a fiexible cord secured to the end of said frame, a take-up roller for said fiexible cord,and means for locking said roller in any predetermined position to adjust the tension of said springs.

3. In a device for overcoming dead-centers, the combination with the hub of a bicycleframe, slotted extensions on said hub, a rotatable shaft movable in said extensions, a spring-controlled lever pinioned to said extensions and adapted to support said shaft, and means to operate said lever.

4. In a bicycle, the combination with a pedal-shaft of spiral springs carried' thereon, means for adjusting the tension of said spiral springs, an auxiliary rotatable device, means for bringing said auxiliary device in and out of coperation with said pedalshaft, and means for causing said spiral springs to support the rotation of said pedal-shaft.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing witnesses.

EMIL JOHOW.

Witnesses:

WOLDEMAR HAUPT, HENRY I-IAsPER. 

